Huh? It's quite clear. The 3G model is the only model that lists GPS as a feature. It lists it as "assisted GPS" because it uses the 3G radio as part of the GPS. Clear as day. They use the term "assisted GPS" because it is "assisted GPS."
Most implementations of assisted GPS rely on the 3G to perform critical functions, such as providing a precise time code, or precise location for nearest GPS satellites. GPS without the 3G would work poorly, or sometimes not at all.
I've read examples of hardware quoting A-GPS and doing no more than cell tower triangulation.
Most of these smartphones have A-GPS because the GPS receiver is built into the cellphone chip itself, potentially reducing board space, power consumption and cost.
I've never used one of these phone/gps devices that has anywhere near the speed and accuracy that a dedicated gps (without cell tower assistance) receiver has - and it's not like they're particularly large, power hungry or costly any more.
In a device like this, I would have liked to have seen them use a few dollars more on parts for a decent, separate GPS receiver on both models.
"GPS without the 3g would work poorly/not at all" ?